The hepatitis C virus has been recently identified as the major causative agent of post-transfusion Non-A, Non-B hepatitis (NANHB), as well as a significant cause of community-acquired NANBH. Materials and methods for obtaining the viral genomic sequences are known. See, e.g. PCT Publication Nos. WO89/04669, WO90/11089 & WO90/14436.
Molecular characterization of the HCV genome indicates that it is a RNA molecule of positive polarity containing approximately 10,000 nucleotides that encodes a polyprotein of about 3011 amino acids. Several lines of evidence suggest that HCV has a similar genetic organization to the viruses of the family Flaviviridae, which includes the flavi- and pestivirus. Like its pesti- and flaviviral relatives, HCV appears to encode a large polyprotein precursor from which individual viral proteins (both structural and non-structural) are processed.
RNA-containing viruses can have relatively high rates of spontaneous mutation, i.e., reportedly on the order of 10.sup.-3 to 10.sup.-4 per incorporated nucleotide. Therefore, since heterogeneity and fluidity of genotype are common in RNA viruses, there may be multiple viral isolates, which may be virulent or avirulent, within the HCV species.
A number of different isolates of HCV have now been identified. The sequences of these isolates demonstrate the limited heterogeneity characteristic of RNA viruses.
Isolate HCV J1.1 is described in Kubo, Y. et al. (1989), Japan. Nucl. Acids Res. 17:10367-10372; Takeuchi, K. et al.(1990), Gene 91:287-291; Takeuchi et al. (1990), J. Gen. Virol. 71:3027-3033; Takeuchi et al. (1990), Nucl. Acids Res. 18:4626.
The complete coding sequences plus the 5'- and 3'-terminal sequences of two independent isolates, "HCV-J" and "BK", are described by Kato et al. and Takamizawa et al, respectively. (Kato et al. (1990), Proc. Natl. Acad. Sci. USA 87:9524-9528; Takamizawa et al (1991), J. Virol. 65:1105-1113.)
Other publications describing HCV isolates are the following;
"HCV-1": Choo et al (1990), Brit. Med. Bull. 46:423-441; Choo et al. (1991), Proc. PA1 "HC-J1" and "HC-J4": Okamoto et al. (1991), Japan J. Exp. Med. 60:167-177. PA1 "HCT 18", "HCT 23", "Th", "HCT 27", "EC1" and "EC10": Weiner et al. (1991), Virol. 180:842-848. PA1 "Pt-1", "HCV-K1" and "HCV-K2": Enomoto et al, There are two major types of hepatitis C virus in Japan. Division of Gastroenterology, Department of Internal Medicine, Kanazawa Medical University, Japan. PA1 Clones "A", "C", "D" & "E": Tsukiyama-Kohara et al., A second group of hepatitis virus, in Virus Genes. PA1 R and R' are amino acid sequences of about 1-2000 amino acids, and are the same or different; PA1 r and r' are 0 or 1, and are the same or different; PA1 V is an amino acid sequence comprising the sequence of an HCV variable domain, wherein the variable domain comprises at least one epitope; PA1 S in an integer .gtoreq.1, representing a selected variable domain; and PA1 n is an integer .gtoreq.1, representing a selected HCV isolate heterogeneous at a given SV with respect to at least one other isolate having a different value for n, and n being independently selected for each x; PA1 x is an integer .gtoreq.1; and with the proviso that amino acid sequences are present in the composition representing a combination selected from the group consisting of (i) 1V.sub.1 and 1V.sub.2, (ii) 1V.sub.1 and 2V.sub.2, and (iii) 1V.sub.1 and 2V.sub.1. PA1 (a) providing an immunoreactive composition as described above; PA1 (b) providing a suitable excipient; and PA1 (c) mixing the immunoreactive composition of (a) with the excipient of (b) in a proportion that provides an immunogenic response upon administration to a mammal. PA1 (a) providing a biological sample suspected of containing antibodies to HCV; PA1 (b) providing an immunoreactive composition described above; PA1 (c) reacting the biological sample of (a) with the immunoreactive composition of (b) under conditions which allow the formation of antigen-antibody complexes; and PA1 (d) detecting the formation of antigen-antibody complexes formed between the immunoreactive composition of (a) and the antibodies of the biological sample of (b), if any.
Natl. Acad. Sci. USA 88:2451-2455; Han et al. (1991), Proc. Natl. Acad. Sci. USA 88:1711-1715; European Patent Publication No. 318,216.
A typical approach to diagnostic and vaccine strategy is to focus on conserved viral domains. This approach, however, suffers from the disadvantage of ignoring important epitopes that may lie in variable domains.
It is an object of this invention to provide polypeptide compositions that are immunologically cross-reactive with multiple HCV isolates, particularly with respect to heterogeneous domains of the virus.